1. Field of the Invention
This invention relates to an hydraulic wheel slide protection system for a vehicle, the system being of the general kind in which pressure fluid is supplied to a wheel brake under the control of a modulator valve, and sensing means is arranged to sense an incipient wheel slide condition of the braked wheel during running of the vehicle, the valve being operative, in response to a signal from the sensing means, to modify the braking force applied to the wheel in order to correct the slide condition.
2. Description of the Prior Art
Some conventional wheel slide protection systems employ a wheel driven pump operating in conjunction with the modulator valve and, for practical reasons, it is advantageous to install the valve close to, or even as a unit with, the pump. This places the pump in a location close to the wheel where only limited space is available and which is also unsatisfactory in that it provides a dirty operating environment.
In other conventional wheel slide protection systems, the pump is driven from the vehicle engine or transmission, or by a separate motor, and this arrangement indicates the placing of the pump in the engine compartment, where equipment is housed in cramped conditions, or elsewhere on the vehicle frame remote from the wheels. In order to minimise and simplify the runs of hydraulic conduit, it is desirable to place the modulator valve near to the pump, thereby adding to the problem of available space.